Cytoreductive surgery (CRS) followed by hyperthermic intraperitoneal chemotherapy (HIPEC) is a process for removing as much peritoneal mesothelioma from the abdomen as possible and killing any cancer cells left behind with a wash of heated medication. It has become the preferred treatment protocol for select mesothelioma patients and has been linked to longer survival.
However, a new study conducted by researchers at the University of Maryland School of Medicine finds that having a condition called thrombocytosis prior to surgery can have a negative impact on mesothelioma survival after CRS/HIPEC.
CRS/HIPEC and Mesothelioma Survival
During CRS, surgeons remove mesothelioma tumors from the surface of the peritoneal membrane, the thin membrane that surrounds the abdominal organs. After the surgery, while the patient is still under anesthesia, chemotherapy drugs are heated and rinsed through the abdomen. The goal is to prevent mesothelioma recurrence for as long as possible.
Although the CRS/HIPEC treatment combination has been associated with prolonged survival in peritoneal mesothelioma patients, it is also a lengthy and complex operation that can cause significant complications and even death.
For optimal outcomes, patients must be carefully selected. But, as the authors of the new University of Maryland study note in the Annals of Surgical Oncology, patient selection criteria for CRS/HIPEC remain “ill-defined”.
Thrombocytosis in Cancer
Thrombocytosis is a disorder in which the body produces too many platelets, the component in blood that is responsible for clotting. It can be caused by a number of underlying conditions such as cancer, iron deficiency, or infection. People with thrombocytosis have a much higher risk of clotting or bleeding complications.
Previous studies have found an association between thrombocytosis and poor outcomes in various other malignancies but the University of Maryland study represents the first time the condition has been linked to mesothelioma outcomes.
The Impact of Platelet Count on Mesothelioma Outcomes
To explore the possible link between platelet count and mesothelioma survival after surgery, the team tracked the cases of 100 mesothelioma patients selected to received CRS/HIPEC at The Greenebaum Comprehensive Cancer Center between January 2006 and December 2015. All of the patients had high-grade epithelioid mesothelioma and their average age was 54.
The median overall survival for all of the patients was 32.8 months, but there was a significant difference in survival between the patients with and without thrombocytosis.
“Median overall survival in patients with elevated versus normal platelet counts were 13 and 58 months, respectively,” writes lead author Yue Li. “Compared with patients with normal platelet counts, patients with elevated counts had significantly greater residual disease after operation.”
Although the researchers took a number of factors into consideration, including suboptimal resection and high tumor burden, elevated preoperative platelet count was independently associated with poor mesothelioma outcomes. Having thrombocytosis, they conclude, can be a sign of an especially aggressive mesothelioma tumor and should be considered a factor in selection for CRS/HIPEC surgery.
Li, Y, et al, “Preoperative Thrombocytosis Predicts Shortened Survival in Patients with Malignant Peritoneal Mesothelioma Undergoing Operative Cytoreduction and Hyperthermic Intraperitoneal Chemotherapy”, Marych 21, 2017, Annals of Surgical Oncology, Epub ahead of print